Hey You Guys and Gals...well thanks for your input.
Quickly to answer a few questions...
Noidea the cops could check for fingerprints on my attache case but it wouldn't hold up for proving anything in court as anyone who lived in the same house or was very frequently here, could just claim they went into my room for some innocent purpose and accidently touched the case. If the fingerprints were of someone who didn't have normal access that would be a different story but regardless the cops didn't want to even investigate.
Joy, regarding finding better roommates...well I had already given my housemate written notice about two days prior to this that I was moving out at the end of this month. This just confirms that this is a smart move.
Plmkrzy, if I knew for sure who took the money it would be a different story. I don't like the emotional drama that goes with making a wrong judgement and falsely blaming someone.
ChiChiMama, my guess as to why both envelopes didn't vanish is that the one that dissappeared was in the tray area of my attache and would be easily viewable when opened but the other envelope was inside a zippered pocket. Thus, if someone was in a hurry, they would only see the one envelope and see it was thick with money. It is maybe a tiny bit of possiblity that I could have simply lost the money in an accidental opening as you suggest but I'm not really giving that much credit as I'm very careful when I'm outside my house with the attache. Still, strange stuff happens so I can't completely rule it out.
Lisa, my renter's insurance doesn't cover any cash loses. I didn't file a police report because it is just too open ended at this time as to what happened.
Thanks Syn and Dino for your suggestion about the minicam. I actually had one once before and did exactly this with it. In my current situation, I really never had any reason to suspect any negative things would happen because there was absolutely no signs beforehand of potential problems. I've for instance deliberately left some money (about $50)laying around in easy view in my room to see if anything happened to it, and nada..zip, nothing. Typically if you see someone failing a small test like this, it is a sign that trouble is living with you. However, goes to show that no test is perfect.
Ballistic, that is really my strategy but I'm going to be out of here in a week and living in a different part of the state. My guess is that if he did do this, he is smart enough to hold off spending any money until I'm gone.
Thanks again for all your input and suggestions.